1. Field of the Invention
The present invention relates to a disk recording/reproducing device for performing recording/reproducing relative to a recording/reproducing disk, such as a compact disk.
2. Description of the Prior Art
In a known disk recording/reproducing device, a disk is pressed onto a turntable by a movable presser member so that the disk is held on the turntable due to a frictional force caused by a pressing force of the presser member. In another known disk recording/reproducing device, a center hole of a disk is matched with a fitting part of a turntable and then the disk is forcibly pressed onto the turntable manually or by means of a loading/unloading mechanism so that a plurality of retaining members urgingly engage with an inner periphery (defining the center hole) of the disk to retain the disk on the turntable.
JP-A-8-180565 describes another disk recording/reproducing device, which will be explained hereinbelow with reference to FIGS. 11A to 11C.
In FIGS. 11A to 11C, numeral 24 denotes a turntable for retaining a disk (not shown) at a disk positioning portion 29 and rotating it. Numeral 25 denotes retaining members radially arranged along the circumference of the disk positioning portion 29 of the turntable 24. Each of the retaining members 25 can move forward (radially outward) and backward (radially inward) and, upon moving forward, the retaining members 25 engage with the inner periphery (defining a center hole) of the disk so as to retain the disk on the turntable 24. Numeral 26 denotes a loading/unloading member comprising a shaft member 30 received in an elongate hole of the turntable 24 and an engaging portion projected from the circumference of the turntable 24. The loading/unloading member 26 is rotatable relative to the turntable 24 at a given angle by operating the engaging portion.
Now, an operation of the disk recording/reproducing device shown in FIGS. 11A to 11C will be explained. First, during forward rotation of the turntable 24, a stopper (not shown) integral with a pickup is moved from the right in the figures to engage with the engaging portion of the loading/unloading member 26. This causes the retaining members 25 to advance or move forward so that the disk is retained on the turntable 24. On the other hand, during reverse rotation of the turntable 24, the engaging portion of the loading/unloading member 26 engages with the stopper of the pickup in a reverse direction. This causes the retaining members 25 to retreat or move backward so that the disk is released.
In the foregoing prior art using the presser member, the presser member as well as a vertical external force for pressing the presser member toward the turntable are required. Moreover, a space is required in the device for movement of the presser member for loading/unloading the disk.
Further, in the foregoing prior art where the disk is forcibly pressed onto the turntable and retained by the retaining members, external forces are required for loading/unloading the disk. Moreover, since the disk is subjected to warp upon loading/unloading, long strokes are required in vertical directions. This necessitates provision of a large space in the device, and renders the loading of the disk unreliable.
Further, in the structure of JP-A-8-180565, since the forward and backward movement of the retaining members 25 is carried out based on rotation of the disk, it is possible that a hand, the loading/unloading mechanism or other components may come in contact with a recording surface of the disk upon loading/unloading the disk. If it occurs, a flow may be caused extensively on the disk to disable recording/reproducing relative to the disk.